A family of thermogelling cationic copolymers containing polyethylenimine and polypropylene glycol

Abstract

Described herein are compositions containing branched polyethylenimine and polypropylene glycol covalently bonded to the branched polyethyleneimine, where a molar ratio of the propylene glycol to the branched polyethylenimine is more than 3.35:1, and the polypropylene glycol is hydrophobic. The compositions may be used as a hydrogel and changes between a solution phase and a gel phase by changes in pH or temperature.

1 . A composition comprising branched polyethylenimine and polypropylene glycol covalently bonded to the branched polyethyleneimine, wherein a molar ratio of the propylene glycol to the branched polyethylenimine is more than 3.35:1, and the polypropylene glycol is hydrophobic and has mole average weight of at least 500 Da, the branched polyethylenimine has a weight average molecular weight of at least 500 Da. 
     
     
         2 . The composition according to  claim 1 , wherein a first end of the propylene glycol is capped with an aliphatic group, an aryl group, or an aralkyl group in any combinations thereof, and a second end of the propylene glycol is covalently bonded to the branched polyethylenimine. 
     
     
         3 . The composition according to  claim 2 , wherein the propylene glycol is capped with the aliphatic group, preferably a C1 to C6 alkyl group. 
     
     
         4 . The composition according to  claim 1 , wherein the propylene glycol has a number average molecular weight from 500 Da to 20 kDa, preferably the polypropylene glycol has a number average molecular weight from 1 kDa to 10 kDa. 
     
     
         5 . (canceled) 
     
     
         6 . The composition according to  claim 1 , wherein the branched polyethylenimine has a weight average molecular weight from 500 Da to 50 kDa, preferably from 5 kDa to 50 kDa. 
     
     
         7 . The composition according to  claim 6 , wherein the branched polyethylenimine has a weight average molecular weight from 10 kDa to 40 kDa. 
     
     
         8 . The composition according to  claim 1 , wherein the branched polyethylenimine has a degree of branching from 5% to 50%. 
     
     
         9 . The composition according to  claim 1 , wherein the polypropylene glycol is covalently bonded to the branched polyethyleneimine via a functional group selected from the group consisting of a carbamate, a carbonate, a carbamide, an ester, an amide, an ether, an amine, a triazole, and any combinations thereof, preferably the carbamate, the amide, the ether, the amine, the triazole, and any combinations thereof. 
     
     
         10 . The composition according to  claim 1 , wherein the molar ratio of propylene glycol to polyethylenimine is from more than 3.35:1 to 40:1. 
     
     
         11 . The composition according to  claim 10 , wherein the branched polyethylenimine is unquarternised, and the molar ratio of propylene glycol to branched polyethylenimine is from 7:1 to 35:1, more preferably the molar ratio is from 10:1 to 25:1 or from 15:1 to 20:1 or from 17:1 to 19:1. 
     
     
         12 . (canceled) 
     
     
         13 . The composition according to  claim 1 , wherein the branched polyethylenimine comprises from 1 mol % to 50 mol % of nitrogen atoms quarternised with a second aryl group, a second aliphatic group, or a second aralkyl group in any combinations thereof, and the molar ratio of propylene glycol to polyethylenimine is more than 8.13:1, preferably the polyethylenimine comprises 1 mol % to 30 mol % of nitrogen atoms quarternised. 
     
     
         14 . The composition according to  claim 13 , wherein the molar ratio of propylene glycol to branched polyethylenimine is from more than 8.13:1 to 60:1, preferably the molar ratio is from 15:1 to 60:1, more preferably the molar ratio is from 15:1 to 50:1, even more preferably the molar ratio is from 15:1 to 40:1. 
     
     
         15 . The composition according to  claim 1 , wherein the composition essentially excludes polyethylene glycol. 
     
     
         16 . The composition according to  claim 1 , further comprising a third polymer up to 20 weight percent of the composition, wherein the third polymer is different from polyethylenimine and polypropylene glycol. 
     
     
         17 . The composition according to  claim 1 , wherein branched polyethylenimine and polypropylene glycol are the only polymers present, preferably the composition consists essentially of branched polyethylenimine and polypropylene glycol. 
     
     
         18 . The composition according to  claim 1  further comprising water, and preferably a buffer solution. 
     
     
         19 . (canceled) 
     
     
         20 . The composition according to  claim 18  further comprising at least one of the following: a therapeutic agent, a protein, and a nucleic acid sequence. 
     
     
         21 . A method of capturing carbon dioxide the method comprises capturing carbon dioxide with the composition according to  claim 1 . 
     
     
         22 . A method of recovering a metal from waste, the method comprises recovering the metal from waste with the composition according to  claim 1 . 
     
     
         23 . The composition according to  claim 9 , wherein the functional group is the carbamate.